Brown pelicans reportedly "Dumpster diving" in the Crescent City Harbor are becoming covered in fish oil, a substance causing the same external symptoms as a petroleum oil spill.

Fifteen birds -- 13 pelicans and two Western gulls -- were in the care of Humboldt Wildlife Care Center in Bayside on Monday after a weekend of bird rescuing.

John Kelsey, president of the center's board of directors, said they have cleaned about five or six birds so far and are working on cleaning the rest this week. He said two of the birds brought in this weekend had to be euthanized due to their deteriorating health.

The center and the Arcata-based Bird Ally X rescued more than two dozen juvenile brown pelicans from the Crescent City Harbor after receiving word Wednesday that the birds had gotten into fish waste totes at the harbor's cleaning station. Harbor Master Richard Young said the harbor has three bins, provided for fishermen to dump their fish carcasses after cleaning.

The issue may be that fishermen who are using some of the waste as bait may be removing the lids and forgetting to put them back on, or the birds were getting into the hole in the middle of the lid. The Humboldt Wildlife Care Center has fitted the bins with new trapdoor lids to remedy the problem, and the district is sending patrols out to make sure the lids stay on.

Young said he wasn't aware that the birds could become covered from the bins.

"Brown pelicans are kind of an iconic bird; nobody wants anything bad to happen to them," he said. "Who knew they could get sick from trying to eat fish."

Bird Ally X's Monte Merrick said the oil disturbs the structure of water birds' feathers, which have little hooks and barbs that form a protective waterproof mesh. Without this protection, birds can get hypothermic when they enter the water. Instead, birds stop entering the water to feed and could starve.

Merrick compares it to a washcloth. While water poured on a washcloth may not penetrate it, water can penetrate a washcloth with soap on it.

"A dime-size drop of petroleum is like a puncture in its dry suit," he said, adding that sea birds should always be dry. "If you look at a pelican and he looks wet, you're looking at a bird in trouble."

California Department of Fish and Game environmental scientist Jeff Dayton said the fish oil is a problem, although it may not reach the scale of a petroleum oil spill. He said there was a similar incident in 2007 when birds got into commercial pots in Eureka.

Fish and Game's Office of Spill Prevention and Response is partnered with the Oiled Wildlife Care Network, the world's only oiled wildlife response organization. The agencies are mandated to treat the effects of petroleum spills and hold companies responsible for spills.

Dayton said there is no violation in these fish oil cases, but public education and rescues are still important.

"We're not going to start charging individual fishermen that are trying to do the right thing," he said.

Dayton said this is where organizations such as the center and Bird Ally X play an important role.

Merrick is hoping the birds will make it out of captivity within 10 days of their rescue, but both he and Kelsey said the two nonprofits have limited resources.

"These pelicans are huge; they eat a lot of fish and take up a lot of space," Kelsey said.

The group, which is funded by public donations, is looking for help from the public in the form of monetary donations, gift cards to local hardware stores, tools for building cages, sheets and towels, or volunteers.